Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references (leaves 65-68). Also available in electronic version.

Thesis (M.Sc.)--City University of Hong Kong, 2005. / At head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials engineering & nanotechnology dissertation. Title from title screen (viewed on Aug. 31, 2006) Includes bibliographical references.

Thesis (M.S.)--Ohio State University, 2007. / Includes bibliographical references (leaves 148-152). Available online via OhioLINK's ETD Center

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 87-91). Also available on the Internet.

RAMOS, S. P. Análise da viabilidade técnica dos levantamentos de baixo custo de perfil e irregularidade longitudinal de pavimento com o uso de acelerômetros controlados por arduino auxiliado por bicicleta. 2017. 113 f. Dissertação (Mestrado em Engenharia de Transportes)–Centro de Tecnologia, Universidade Federal do Ceará, Fortaleza, 2017. / Submitted by Marlene Sousa (mmarlene@ufc.br) on 2017-08-29T16:33:29Z No. of bitstreams: 1 2017_dis_spramos.pdf: 6011113 bytes, checksum: c11cfa0615a6da726476a6166777b7f2 (MD5) / Approved for entry into archive by Marlene Sousa (mmarlene@ufc.br) on 2017-08-29T16:34:48Z (GMT) No. of bitstreams: 1 2017_dis_spramos.pdf: 6011113 bytes, checksum: c11cfa0615a6da726476a6166777b7f2 (MD5) / Made available in DSpace on 2017-08-29T16:34:48Z (GMT). No. of bitstreams: 1 2017_dis_spramos.pdf: 6011113 bytes, checksum: c11cfa0615a6da726476a6166777b7f2 (MD5) Previous issue date: 2017-06-30 / User safety and rolling comfort are functional parameters that can be evaluated, among other criteria, by roughness . Given that there is a strong relation between the profile and the longitudinal irregularities of a pavement, this affinity allows to analyze the evolution of that parameter. In order to carry out the survey of a longitudinal profile of a pavement and the evaluation of roughness , according to the current norms, we can mention, respectively, the level and sighting methods and the laser profilometer. The first one demands a lot of time and physical effort from the operators and the second, a lot of financial resources, since it is a n equipment that costs almost R $ 400,000 ,00 . Thus, it is reasonable to analyze the feasibility of the use of new technologies in order to reconstruct a trajectory related to the longitudinal profile of a pavement and to evaluate an d monitor the evolution of roughness in a practical and economical way. One of the ways to obtain the profile and to evaluate the roughness in this work was the use of inertial sensors, such as an accelerometer. This sensor controlled by an a rduino microco ntroller provides acceleration data, which, after processing the data using the Matlab, Excel, Proval and Minitab software, sought to verify the quality and behavior of the measured signals in order to evaluate the capacity Of the sensor to reconstruct the longitudinal profile and the potential of the equipment to evaluate the longitudinal irregularities of a pavement. In the data collection stage, a Scottish fork and an air rail trolley were used in the laboratory, and a bicycle, with which several passes were made in an experimental section located in the Pici Campus of the Federal University of Ceará. The acceleration data obtained by the accelerometer were processed through digital signal filters and correlated with the International Roughness Index (IRI ) values. By the analysis of the results, it was possible to conclude that the equipment is not efficient to obtain the longitudinal profile of a pavement, due to the low speed of the bicycle. However, the accelerometer controlled by arduino had a high pot ential to evaluate the roughness of a pavement, with 85% of satisfactory results. / A segurança dos usuários e o conforto ao rolamento são parâmetros funcionais que podem ser avaliados, entre outros critérios, pela irregularidade longitudinal. Dado que há uma forte relação entre o perfil e as irregularidades longitudinais de um pavimento, esta afinidade permite analisar a evolução daquele parâmetro. Para se executar o levantamento de perfil longitudinal de um pavimento e a avaliação de irregularidad e longitudinal, de acordo com as normas atuais, pode - se citar, respectivamente, os métodos de nível e mira e do perfilômetro a laser . O primeiro demanda muito tempo e esforço físico dos operadores e o segundo, muitos recursos financeiros, por ser um equipa mento que chega a custar quase R$ 400.000,00 . Dessa forma, torna - se razoável analisar a viabilidade do uso de novas tecnologias com o intuito de se reconstruir uma trajetória referente ao perfil longitudinal de um pavimento e avaliar e monitorar a evolução da irregularidade longitudinal de modo prático e econômico. Uma das maneiras para se obter o perfil e avaliar a irregularidade longitudinal , neste trabalho, foi pelo uso de sensores inerciais, como um acelerômetro. Este sensor controlado por um microcontr olador arduino fornece dados de aceleração, dos quais , após o processamento dos dados pelos softwares Matlab, Excel, Proval e Minitab, procurou - se verificar a qualidade e o comportamento dos sinais medidos com o objetivo de se avaliar a capacidade de o se nsor reconstruir o perfil longitudinal e o potencial do equipamento de avaliar as irregularidades longitudinais de um pavimento. Na etapa de obtenção dos dados, foram utilizados um garfo escocês e um carrinho de trilho de ar , em laboratório, e uma biciclet a, com a qual foram realizadas várias passagens em um trecho experimental localizado no Campus do Pici da Universidade Federal do Ceará. Os dados de aceleração obtidos pelo acelerômetro foram processados através de filtros digitais de sinais e correlaciona dos com os valores do Índice Internacional de Irregularidade ( International Roughness Index – IRI). Pela análise dos resultados , foi possível concluir que o equipamento não é eficiente para a obtenção do perfi l longitudinal de um pavimento , devido à baixa velocidade da bicicleta. No entanto, o acelerômetro controlado por a rduino apresentou elevado potencial para avaliar a irregularidade longitudinal de um pavimento, com 85% de resultados satisfatórios.

O presente estudo teve como objetivo avaliar quantitativamente a alteração na rugosidade superficial e o desgaste de resinas compostas com diferentes características de matriz orgânica e de carga inorgânica frente ao teste de escovação simulada e ciclagem de pH. Foram testadas três resinas compostas: Filtek Z250 (Bis-GMA, microhíbrida), Filtek Z350 (Bis-GMA, nanoparticulada) e Filtek P90 (silorano, microhíbrida)(3M-ESPE). Para cada resina foram confeccionados dois grupos (n=10) de corpos de prova retangulares (15mmx5mmx4mm). Após a polimerização e polimento adequado dos espécimes, a rugosidade inicial (Ra) foi obtida pela média de três leituras com o Rugosímetro Hommel T1000. Metade de cada corpo de prova foi protegida com esmalte de unha e um dos grupos de cada resina foi submetido a um protocolo de ciclagem de pH (desmineralização-pH 4,3 e remineralização-pH 7,0). Para o teste de abrasão foram realizados 100.000 ciclos de escovação simulada, permanecendo a metade protegida como grupo controle. Na metade escovada foi verificada a rugosidade final, seguindo os mesmos parâmetros iniciais, e o desgaste (µm) foi quantificado pela média de 3 leituras do perfil real abrangendo as duas superfícies (controle e escovada). Os resultados obtidos (ANOVA, teste t Student e Tukey, p<0.05) mostraram diferenças significantes para o desgaste e alteração de rugosidade entre as resinas testadas. A maior média de desgaste foi apresentada pela Filtek P90 (11,505µm±5,690) com diferença significante para a Filtek Z250 (4,191µm±1,725) e para a Filtek Z350 (4,163µm±0,947), sendo que a ciclagem de pH afetou apenas o desgaste da resina Filtek P90 (15,305µm±5,409). Verificou-se aumento da média de rugosidade superficial para as resinas Filtek Z250 e Z350 após escovação simulada, enquanto que a resina Filtek P90 apresentou comportamento contrário, com diferenças estatisticamente significantes (p<0,05). As imagens de microscopia eletrônica de varredura apresentaram-se coerentes com os resultados quantitativos obtidos. / The present study aimed to quantitatively evaluate the surface roughness alteration and wear of resin composites with different characteristics of organic matrix and inorganic filler when submitted to simulated toothbrushing abrasion and pH cycling. Three different resin composites were evaluated: Filtek Z250 (Bis-GMA, microhybrid), Filtek Z350 (Bis-GMA, nanofilled) and Filtek P90 (silorane based, microhybrid) (3M-ESPE). For each resin two groups (n=10) of rectangular specimens (15mmX5mmX4mm) were made. After polymerization and polishing, the initial roughness (Ra) was evaluated by the average of three tracings using a roughness tester Hommel T1000 basic. Half of each specimen was protect with nail varnish and one group of each resin was submitted to pH cycling (demineralization-pH 4,3 and remineralization-pH 7,0). For the abrasion test 100.000 strokes of simulated toothbrushing was processed. The protected side was maintained as control. Over the brushed side the final roughness was measured with the same initial parameters and wear was quantified by the average of 3 readings of the real profile between the two surfaces (control and brushed side). The obtained results (ANOVA, Student t test and Tukey, p<0.05) showed significant differences of wear and surface roughness alteration between the tested materials. Filtek P90 presented the highest average wear rate (11.505 ± 5.690µm) compared to Z250 (4.191 ± 1.725µm) and Z350 (4.163 ± 0.947µm) and the pH cycling significantly affected the wear of Filtek P90(15.305 ± 5.409 mM). The surface roughness evaluation revealed an increasing on surface roughness for Filtek Z250 and Filtek Z350 after toothbrushing, while Filtek P90 showed an opposite behavior, with statistically significant differences (p<0.05). The scanning electron microscope images were in accordance to the quantitative results obtained.

The growth of barrier-type anodic alumina films formed by anodizing relatively rough substrates has been shown to proceed by high field ionic conduction. As a result of the ionic transport and the induced plasticity, smoothing of the oxide surfaces and the metal/oxide interfaces arises. However, such a smoothing model was deduced from topographical observations and, therefore little insight was gained about the transport mechanism leading to the flattening of the anodized specimens. Recently, the development of porous anodic alumina has been demonstrated to proceed by coupled ionic migration and material flow resulting from the field-induced mechanical stress. For rough metal surfaces, the electric field distribution is non-uniform across the specimen surface. Considering the square-dependence of the electrostrictive stress on the electric field and the distribution of the electric field across surface, a significant gradient of mechanical stress may arise across the anodic oxide layer during anodizing. As a result, stress-driven transport may participate, in addition to high field ionic conduction, to the smoothing of the specimen surface. Transport mechanisms were investigated during anodizing of patterned superpure aluminium specimens, by examination of the distributions of incorporated species, used as markers and tracers. The nature of the migration processes have been determined in correlation with the changes in the concentration of the tracer profiles as well as the variations in the anodic oxide film compositions.

Nas últimas três décadas houve incremento da exigência estética na área odontológica, provocado pela crescente valorização da apresentação pessoal, acompanhada do grande avanço tecnológico dos materiais em suas propriedades físicas e biológicas, o que proporcionou uma utilização clínica cada vez maior. Dentre esses materiais destacam-se as porcelanas odontológicas que vem apresentando excelentes resultados estéticos, sendo empregadas em diferentes situações clinicas. Durante a confecção de restaurações parciais tipo inlay e onlay com porcelanas feldspáticas, o clinico se depara com certos obstáculos. Um deles é o ajuste oclusal da peça protética que, nessas situações, deve ser realizado apenas após a cimentação definitiva, para evitar fraturas ou trincas. Com isso perde-se em algumas regiões o glaze, previamente realizado pelo técnico de laboratório. Isto pode acarretar alterações em sua estrutura com conseqüente aparecimento de trincas, perda de caracterização superficial, redução da resistência, geração de maior tensão durante contatos oclusais e alteração da sua rugosidade superficial. Esta última influenciará decisivamente na aderência bacteriana, acúmulo de biofilme dental, grau de desgaste do elemento antagonista e eficiência mastigatória. O trabalho avaliou in vitro a rugosidade (parâmetro Ra) de uma porcelana feldspática modificada glazeada e submetida a dois sistemas de acabamento e polimento. Os resultados não mostraram diferença estatisticamente significante entre os grupos e a superfície glazeada (P<0,05). / In the last three decades it had an increment of the aesthetic requirement in dentistry area, which became from the increasing valuation of the personal presentation, followed by the great technological advance of the materials in its physical and biological properties, which provided more clinical utilities over the time. Among these materials, the dental porcelains are showing excellent aesthetic results and they are used in different clinical practice situations. During the confection of partial restorations, like feldspathic inlay and onlay, the dentist comes across with certain obstacles. One of them it is the oclusal adjustment of the prosthetic restoration, which on these situations must be done through after the cimentation, to prevent fracture or crack lines. Therefore the glaze is lost in some regions, previously executed by the lab technician. It will be able to cause alterations in its structure and then it will show up same cracks, loss of superficial characterizations, reduction of the resistance, appearence of tension during oclusals contacts and alteration of its surface roughness. The last refer will influence decisively in the bacterial aderance, dental accumulation of biofilm, waste levels of antagonist surface and mastigatory efficience. The present study evaluated in vitro the roughness (Ra parameter) of the modified feldspathic porcelain glazed and submitted to two systems of finishing and intrabucal polishing. The results had not shown estatisticlly significant difference between the tests groups and the control glazing surface group(P<0,05).

Determining bumpiness and inclination of surfaces is very important in many different areas, such as airports and at constructions sites. In this study, a surveying trolley and a remote controlled (RC) car were used to determine the bumpiness of two different surfaces. The aim with this study was to test the accuracy of a surveying trolley and an RC car to see how the accuracy can be increased with different observation methods. Total station, GPS and laser scanner surveying equipments were used, and all observations obtained by them were analysed. The laser scanner data was found to have the best precision. For that reason, it was accepted as the “true” data and it was used for comparing and evaluating other methods. It was found that the trolley and the RC car provided good height information with total stations and they were corresponding to the laser scanner data. When they were used with GPS, the accuracy was much lower. It was concluded that using two total stations is not increasing the accuracy, the RC car and the trolley are good measuring methods but not capable to inspect 1,2 mm tolerance for the floors, and finally, 2-3 cm positioning accuracy is obtainable when using GPS.

Two methods for the measurement of micro-scale stressvariations of press felt surfaces were developed. The methodswere based on a thin plastic film that was coated with anopaque stress-sensitive layer (Cronapress conversion film). Thefilm was compressed between a felt and a smooth surface. Uponapplication of load the opaque layer became partiallytransparent at the locations where load was applied by thesurface fibres of the felt. The degree of transparency was afunction of the locally applied stress. The spatial resolutionof the method was 6.3 µm, which means that even details ofthe order of the diameter of a batt fibre diameter can beresolved. Parameters characterising the stress variations were used toquantitatively describe the extent of the stress variations,the size of the contact areas and the distance between them.The applicability of these contact characterisation parameterswas evaluated in laboratory wet pressing experiments and inpilot paper machine trials for two sets of specially designedpress felts. In general, the dewatering result was mainlyinfluenced by the diameter of the felt surface batt fibres andby the web grammage. For a specific pulp type and operatingconditions a multivariate model was formulated based on themeasured web dryness, web grammage and each contactcharacterisation parameter. The model was able to describe thedewatering capability of the different felts tested. Contactcharacterisation parameters related to contact properties (e.g.contact area ratio) gave the best prediction for low grammagewebs, while parameters related to flow properties (e.g. size ofopenings) gave the best prediction for high grammage webs. Furthermore it was found that at a certain web grammage, thesurface batt fibre diameter did not have an influence on thedewatering result. This grammage was termed "transitiongrammage". Below the transition grammage a fine surface gavesignificantly better dewatering, while the opposite trend wasobserved above the transition grammage. Based on these results,a modified dewatering hypothesis was formulated. Thishypothesis links the non-uniform compression of the wet webwith different dewatering situations for low and high grammagewebs. KeywordsPress felts, Roughness, Smoothness, SurfaceStructure, Uniformity, Wet pressing, Batt fibre, Base weave,Stress variations, Micro-scale. / <p>QCR 20161026</p>